Since I already mentioned it in another thread here, I thought I'd better announce it properly in a new thread.
I'm working on a new Disk Manager (called MSX Disk Explorer) for windows. For the moment I'm developing in 32 bit, but it'll probably also get it's 64 bit version. At the moment it's more or less an empty shell capable of reading the files of a normal DSK image, but I only started the work a couple of days ago and a lot of that went into trrying to get the user interface to behave the way I want. Features that it will DEFINATELY have in the near future are ..
- Extracting Files (all at once, without having to confirm every single one).
- Multi Disk Support (multiple DSK images stitched together)
- Reading and writing back DMK protected disks
- Simple viewers for Basic, Graphics, Text and HexDump (BASIC already works for 99%)
- Working with many disks at the time (atleast 10)
- Moving or copying files between disks
- Dividing files between mutliple disks
- IPS and MIA patching and creating patches
- DOS2 subdirectories
- Harddisk Support
- Full command line support
Features I'd like to have in there are ...
- DPI Support (converting between DMK and DPI where possible)
- Disassembly viewer
But I'm always open for further suggestions and wishes.
Though Linux/*nix support would be nice..(!) (Though Wine might run it otherwise..) 
